import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebServlet("/getParameter")
public class getParameter extends HttpServlet {
    //1、通过query string传递数据
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //前端通过url的query string传递username和password
        String username=req.getParameter("username");
        if(username==null){
            System.out.println("username这个key在query string中不存在！");
        }
        String password=req.getParameter("password");
        if(password==null){
            System.out.println("password这个key在query string中不存在！");
        }
        System.out.println("username="+username+",password="+password);
        resp.getWriter().write("ok");
    }

    //2、通过body传递（form）
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf8");
        //前端通过body，以form表单的格式，传递给服务器
        String username=req.getParameter("username");
        if(username==null){
            System.out.println("username这个key在body中不存在！！！");
        }
        String password=req.getParameter("password");
        if(password==null){
            System.out.println("password这个key在body中不存在！！！");
        }
        System.out.println("username="+username+",password="+password);
        resp.getWriter().write("ok");
    }

    //3、通过body传递数据（json）！！！

}
